Directives for the cleaning and sterilization of reusable medical instruments, and in particular surgical instruments, pose high requirements, which require the surgical instruments to be capable of being dismantled. In particular, the shaft and the operating device, as a rule, can be separated from one another. The operating device comprises as a rule at least two gripping members that can be moved with respect to one another, of which one is coupled with the shaft and the other with a transmission rod that is positioned in the shaft. A movement of the two gripping members in relation to one another results in a movement of the transmission rod within the shaft.
The proximal end of the transmission rod is configured, in particular, as a coupling element for releasable mechanical coupling with a gripping member of the operating device. With different shaft diameters, transmission rods with different cross-sections are used. In particular when the transmission rod is connected with a tool that can be separated from the shaft and therefore can be withdrawn out of the shaft in the distal direction, the size of the coupling element on the proximal end of the transmission rod depends on the cross-section of the shaft.
With medical instruments for micro-invasive procedures, there is a trend toward constantly thinner shafts. This requires constantly smaller coupling elements at the proximal ends of the transmission rods. Therefore, operating devices that conventionally retained the same structure for many different medical instruments cannot continue to be used without modification. Instead, the operating devices must be modified and in the worst case must be constantly adjusted to constantly smaller coupling elements at proximal ends of transmission rods.